An air conditioning system installed in a vehicle is required to be small as a whole due to a limitation of a space. Additionally, the air conditioning system is required to be light for improving a fuel economy of a vehicle. To meet these requirements, in recent years, the evaporator is made light in weight by using a thin material, for example.
However, when the evaporator is lighten in weight, stiffness of each part of the evaporator may decrease, and accordingly a vibration may be likely to occur. Therefore, during an operation of an air conditioning system, a vibration may be generated in the evaporator and be transferred to a vehicle compartment, and a large noise may be generated. A vibration generated by a refrigerant passing through an inside of the evaporator and a vibration (noise) generated by a pulsing motion occurring when a compressor discharges or draws the refrigerant are examples of the vibration generated in the evaporator. The noise generated by the transfer of the vibration is not preferable because the noise makes a driver feel uncomfortable.
In Patent Document 1 discloses an evaporator in which a vibration suppression and heat insulation member is attached on an outer peripheral surface of the evaporator. The vibration suppression and heat insulation member has a two-layer structure. An inner (evaporator side) layer is a vibration suppression layer made of an unvulcanized butyl rubber, and an outer layer is a heat insulation sheet made of a heat insulation material. The unvulcanized butyl rubber (vibration suppression layer) that has a relatively large relative density is adhered to the evaporator.